Effects of Ga adatom migration on formation of lateral p-n tunneling junctions on GaAs(N 11) A patterned substrates

We have investigated how Ga adatom migration effects the abruptness of lateral p-n junctions formed on GaAs( Nl 1)A (N 5 4) patterned substrates by using the amphoteric nature of Si dopant. Ga adatom migration effects the abruptness of lateral p-n junctions through As,/Ga flux ratio modulation in the vicinity of the p-n junctions, and an interband tunneling junction with negative differential resistance characteristics is obtained when Ga adatoms do not migrate from a p-type surface to an n-type surface. The Ga adatom migration from a p-type surface to an n-type surface causes carrier compensation at the p-n junction. A high peak current density of 202 A/cm* with a peak-to-valley ratio of 4.2 was obtained in the lateral tunneling junction formed on the (311)A patterned substrate. This study shows that the control of Ga adatom migration is very important for fabricating lateral tunneling junctions.